We have a bag of things sitting in the house for a few years from a camp I did for kids and no one claimed and we do not whose it is. Do we have to keep it still or can we toss it? Its been 4 years since then.
This is a common question. It is clear, after four years, that there is no point in keeping the thinkgs.
You can either take them for yourselves, give them away, or throw them away.
However, if there are items with simanim present, you should note the items, their approximate value, and their simanim in an Aveidah notebook, so that if somebody comes to claim them you’ll be able to reimburse the loss (this is the advice generally given by Rav Moshe Feinstein).
For simple, everyday items there is unlikely to be a siman, and there won’t be an obligation to do this.